In the case of ABF Freight System, Inc. v. National Labor Relations Board (1993), the U.S Supreme Court ruled in favor of the National Labor Relations Board (NLRB). The dispute arose when ABF Freight System refused to bargain with a union that had been certified by NLRB as an exclusive representative for a group of its employees. The company argued that it was not obligated to negotiate because some members within this unit were supervisors and thus excluded from collective bargaining under federal labor law. However, NLRB held that these individuals were not supervisors but rather "lead men" who did not have genuine managerial authority over other workers. On appeal, the Supreme Court upheld NLRB's decision stating that substantial evidence supported their conclusion about these employees' status and role within the company.

The dissenting opinion in the case of ABF Freight System, Inc. v. National Labor Relations Board disagreed with the majority's interpretation of section 8(a)(5) and (1) of the National Labor Relations Act. The dissent argued that these sections do not require an employer to bargain over a decision to close part of its business for economic reasons if it has already bargained about this issue during contract negotiations and reached an impasse. They contended that forcing employers into further bargaining would undermine their ability to make necessary business decisions quickly and efficiently, which could potentially harm both businesses and employees in the long run. Furthermore, they believed that such a requirement contradicts previous court rulings on similar cases where employers were allowed to act unilaterally after reaching an impasse in negotiations.